gtk4: use the FixedContainer overlay for mouse events after all

Remove gtk_widget_set_can_target on the overlay so that when we put
native gtk widgets into the overlay they get events and can be
interacted with.

The DrawingArea is 'underneath' the overlay. So just move the mouse
event handlers to the overlay itself so we can still appear to interact
with the DrawingArea.

Change-Id: I43056c5ee6228af85a194c1baa9f83c58b3e389d
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/118680
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>

1 files changed, 32 insertions, 27 deletions

diff --git a/vcl/unx/gtk3/gtkframe.cxx b/vcl/unx/gtk3/gtkframe.cxx
index b3647b6a8296..71b8673ee11e 100644
--- a/vcl/unx/gtk3/gtkframe.cxx
+++ b/vcl/unx/gtk3/gtkframe.cxx
@@ -768,7 +768,7 @@ void GtkSalFrame::moveWindow( tools::Long nX, tools::Long nY )
 
 void GtkSalFrame::widget_set_size_request(tools::Long nWidth, tools::Long nHeight)
 {
-    gtk_widget_set_size_request(GTK_WIDGET(m_pDrawingArea), nWidth, nHeight );
+    gtk_widget_set_size_request(GTK_WIDGET(m_pFixedContainer), nWidth, nHeight );
 }
 
 void GtkSalFrame::window_resize(tools::Long nWidth, tools::Long nHeight)
@@ -873,7 +873,7 @@ GtkWidget *GtkSalFrame::getMouseEventWidget() const
 #if !GTK_CHECK_VERSION(4,0,0)
     return GTK_WIDGET(m_pEventBox);
 #else
-    return GTK_WIDGET(m_pDrawingArea);
+    return GTK_WIDGET(m_pFixedContainer);
 #endif
 }
 
@@ -922,8 +922,8 @@ void GtkSalFrame::InitCommon()
     m_pFixedContainer = GTK_FIXED(gtk_fixed_new());
     m_pDrawingArea = GTK_DRAWING_AREA(gtk_drawing_area_new());
 #endif
-    gtk_widget_set_can_focus(GTK_WIDGET(m_pDrawingArea), true);
-    gtk_widget_set_size_request(GTK_WIDGET(m_pDrawingArea), 1, 1);
+    gtk_widget_set_can_focus(GTK_WIDGET(m_pFixedContainer), true);
+    gtk_widget_set_size_request(GTK_WIDGET(m_pFixedContainer), 1, 1);
 #if !GTK_CHECK_VERSION(4,0,0)
     gtk_container_add( GTK_CONTAINER(m_pEventBox), GTK_WIDGET(m_pFixedContainer) );
 #else
@@ -932,13 +932,12 @@ void GtkSalFrame::InitCommon()
     gtk_grid_attach(m_pTopLevelGrid, GTK_WIDGET(m_pOverlay), 0, 0, 1, 1);
     gtk_overlay_set_child(m_pOverlay, GTK_WIDGET(m_pDrawingArea));
     gtk_overlay_add_overlay(m_pOverlay, GTK_WIDGET(m_pFixedContainer));
-    gtk_widget_set_can_target(GTK_WIDGET(m_pFixedContainer), false);
 #endif
 
     GtkWidget *pEventWidget = getMouseEventWidget();
 #if !GTK_CHECK_VERSION(4,0,0)
-    gtk_widget_set_app_paintable(GTK_WIDGET(m_pDrawingArea), true);
-    gtk_widget_set_redraw_on_allocate(GTK_WIDGET(m_pDrawingArea), false);
+    gtk_widget_set_app_paintable(GTK_WIDGET(m_pFixedContainer), true);
+    gtk_widget_set_redraw_on_allocate(GTK_WIDGET(m_pFixedContainer), false);
 #endif
 
 #if GTK_CHECK_VERSION(4,0,0)
@@ -1003,14 +1002,14 @@ void GtkSalFrame::InitCommon()
 #endif
 
 #if !GTK_CHECK_VERSION(4,0,0)
-    g_signal_connect( G_OBJECT(m_pDrawingArea), "draw", G_CALLBACK(signalDraw), this );
-    g_signal_connect( G_OBJECT(m_pDrawingArea), "size-allocate", G_CALLBACK(sizeAllocated), this );
+    g_signal_connect( G_OBJECT(m_pFixedContainer), "draw", G_CALLBACK(signalDraw), this );
+    g_signal_connect( G_OBJECT(m_pFixedContainer), "size-allocate", G_CALLBACK(sizeAllocated), this );
 #else
     gtk_drawing_area_set_draw_func(m_pDrawingArea, signalDraw, this, nullptr);
-    g_signal_connect( G_OBJECT(m_pDrawingArea), "resize", G_CALLBACK(sizeAllocated), this );
+    g_signal_connect(G_OBJECT(m_pDrawingArea), "resize", G_CALLBACK(sizeAllocated), this);
 #endif
 
-    g_signal_connect( G_OBJECT(m_pDrawingArea), "realize", G_CALLBACK(signalRealize), this );
+    g_signal_connect(G_OBJECT(m_pFixedContainer), "realize", G_CALLBACK(signalRealize), this);
 
 #if !GTK_CHECK_VERSION(4,0,0)
     GtkGesture *pSwipe = gtk_gesture_swipe_new(pEventWidget);
@@ -1043,6 +1042,8 @@ void GtkSalFrame::InitCommon()
     g_signal_connect(pFocusController, "leave", G_CALLBACK(signalFocusLeave), this);
     gtk_widget_set_focusable(pEventWidget, true);
     gtk_widget_add_controller(pEventWidget, pFocusController);
+    if (GTK_IS_WINDOW(m_pWindow)) // i.e. not if it's a GtkEventBox which doesn't have the property (presumably?)
+        m_nSetFocusSignalId = g_signal_connect( G_OBJECT(m_pWindow), "notify::focus-widget", G_CALLBACK(signalSetFocus), this );
 #endif
 #if !GTK_CHECK_VERSION(4,0,0)
     g_signal_connect( G_OBJECT(m_pWindow), "map-event", G_CALLBACK(signalMap), this );
@@ -1190,7 +1191,7 @@ void GtkSalFrame::DisallowCycleFocusOut()
     // set container without can-focus and focus will tab between
     // the native embedded widgets using the default gtk handling for
     // that
-    gtk_widget_set_can_focus(GTK_WIDGET(m_pDrawingArea), false);
+    gtk_widget_set_can_focus(GTK_WIDGET(m_pFixedContainer), false);
 }
 
 bool GtkSalFrame::IsCycleFocusOutDisallowed() const
@@ -1206,12 +1207,14 @@ void GtkSalFrame::AllowCycleFocusOut()
     // enable/disable can-focus as control enters and leaves
     // embedded native gtk widgets
     m_nSetFocusSignalId = g_signal_connect(G_OBJECT(m_pWindow), "set-focus", G_CALLBACK(signalSetFocus), this);
+#else
+    m_nSetFocusSignalId = g_signal_connect(G_OBJECT(m_pWindow), "notify::focus-widget", G_CALLBACK(signalSetFocus), this);
 #endif
 
     // set container without can-focus and focus will tab between
     // the native embedded widgets using the default gtk handling for
     // that
-    gtk_widget_set_can_focus(GTK_WIDGET(m_pDrawingArea), true);
+    gtk_widget_set_can_focus(GTK_WIDGET(m_pFixedContainer), true);
 }
 
 
@@ -2870,9 +2873,9 @@ void GtkSalFrame::GrabFocus()
     if (GTK_IS_EVENT_BOX(m_pWindow))
         pGrabWidget = GTK_WIDGET(m_pWindow);
     else
-        pGrabWidget = GTK_WIDGET(m_pDrawingArea);
+        pGrabWidget = GTK_WIDGET(m_pFixedContainer);
 #else
-    pGrabWidget = GTK_WIDGET(m_pDrawingArea);
+    pGrabWidget = GTK_WIDGET(m_pFixedContainer);
 #endif
     // m_nSetFocusSignalId is 0 for the DisallowCycleFocusOut case where
     // we don't allow focus to enter the toplevel, but expect it to
@@ -3603,7 +3606,7 @@ void GtkSalFrame::DrawingAreaFocusInOut(SalEvent nEventType)
         if (GTK_IS_WINDOW(m_pWindow))
         {
             GtkWidget* pFocusWindow = gtk_window_get_focus(GTK_WINDOW(m_pWindow));
-            bFocusInAnotherGtkWidget = pFocusWindow && pFocusWindow != GTK_WIDGET(m_pDrawingArea);
+            bFocusInAnotherGtkWidget = pFocusWindow && pFocusWindow != GTK_WIDGET(m_pFixedContainer);
         }
         if (!bFocusInAnotherGtkWidget)
             m_pIMHandler->focusChanged(nEventType == SalEvent::GetFocus);
@@ -3636,7 +3639,7 @@ gboolean GtkSalFrame::signalFocus( GtkWidget*, GdkEventFocus* pEvent, gpointer f
         if (GTK_IS_WINDOW(pThis->m_pWindow))
         {
             GtkWidget* pFocusWindow = gtk_window_get_focus(GTK_WINDOW(pThis->m_pWindow));
-            bFocusInAnotherGtkWidget = pFocusWindow && pFocusWindow != GTK_WIDGET(pThis->m_pDrawingArea);
+            bFocusInAnotherGtkWidget = pFocusWindow && pFocusWindow != GTK_WIDGET(pThis->m_pFixedContainer);
         }
         if (!bFocusInAnotherGtkWidget)
             pThis->m_pIMHandler->focusChanged( pEvent->in != 0 );
@@ -3657,7 +3660,7 @@ gboolean GtkSalFrame::signalFocus( GtkWidget*, GdkEventFocus* pEvent, gpointer f
         if (GTK_IS_EVENT_BOX(pThis->m_pWindow))
             pGrabWidget = GTK_WIDGET(pThis->m_pWindow);
         else
-            pGrabWidget = GTK_WIDGET(pThis->m_pDrawingArea);
+            pGrabWidget = GTK_WIDGET(pThis->m_pFixedContainer);
         bool bHasFocus = gtk_widget_has_focus(pGrabWidget);
         pThis->CallCallbackExc(bHasFocus ? SalEvent::GetFocus : SalEvent::LoseFocus, nullptr);
     }
@@ -3678,32 +3681,34 @@ void GtkSalFrame::signalFocusLeave(GtkEventControllerFocus*, gpointer frame)
 }
 #endif
 
-#if !GTK_CHECK_VERSION(4, 0, 0)
 // change of focus between native widgets within the toplevel
+#if !GTK_CHECK_VERSION(4, 0, 0)
 void GtkSalFrame::signalSetFocus(GtkWindow*, GtkWidget* pWidget, gpointer frame)
+#else
+void GtkSalFrame::signalSetFocus(GtkWindow*, GParamSpec*, gpointer frame)
+#endif
 {
     GtkSalFrame* pThis = static_cast<GtkSalFrame*>(frame);
 
-    GtkWidget* pGrabWidget;
-    if (GTK_IS_EVENT_BOX(pThis->m_pWindow))
-        pGrabWidget = GTK_WIDGET(pThis->m_pWindow);
-    else
-        pGrabWidget = GTK_WIDGET(pThis->m_pDrawingArea);
+    GtkWidget* pGrabWidget = GTK_WIDGET(pThis->m_pFixedContainer);
 
     GtkWidget* pTopLevel = widget_get_toplevel(pGrabWidget);
     // see commentary in GtkSalObjectWidgetClip::Show
     if (pTopLevel && g_object_get_data(G_OBJECT(pTopLevel), "g-lo-BlockFocusChange"))
         return;
 
+#if GTK_CHECK_VERSION(4, 0, 0)
+    GtkWidget* pWidget = gtk_window_get_focus(GTK_WINDOW(pThis->m_pWindow));
+#endif
+
     // tdf#129634 interpret losing focus as focus passing explicitly to another widget
     bool bLoseFocus = pWidget && pWidget != pGrabWidget;
 
     // do not propagate focus get/lose if floats are open
     pThis->CallCallbackExc(bLoseFocus ? SalEvent::LoseFocus : SalEvent::GetFocus, nullptr);
 
-    gtk_widget_set_can_focus(GTK_WIDGET(pThis->m_pDrawingArea), !bLoseFocus);
+    gtk_widget_set_can_focus(GTK_WIDGET(pThis->m_pFixedContainer), !bLoseFocus);
 }
-#endif
 
 void GtkSalFrame::WindowMap()
 {
@@ -3770,7 +3775,7 @@ gboolean GtkSalFrame::signalKey(GtkWidget* pWidget, GdkEventKey* pEvent, gpointe
     if (GTK_IS_WINDOW(pThis->m_pWindow))
     {
         GtkWidget* pFocusWindow = gtk_window_get_focus(GTK_WINDOW(pThis->m_pWindow));
-        bFocusInAnotherGtkWidget = pFocusWindow && pFocusWindow != GTK_WIDGET(pThis->m_pDrawingArea);
+        bFocusInAnotherGtkWidget = pFocusWindow && pFocusWindow != GTK_WIDGET(pThis->m_pFixedContainer);
         if (bFocusInAnotherGtkWidget)
         {
             if (!gtk_widget_get_realized(pFocusWindow))